1. Field of the Invention
The present invention relates to a spring feeder for arranging coil-type springs (in particular, springs of a very small size) in a row along the compression-elongation direction thereof and feeding the springs in a state suitable for an operation to an operator, whereby spring jamming caused by a defective spring in a conveying path for feeding of the feeder can be released.
2. Description of the Related Art
Spring feeders are known that serve to arrange a large number of coil-type springs in a row along the compression-elongation direction thereof and feed the springs one by one in a state suitable for an operation to an operator. In such a spring feeder, a large number of springs are loaded into a container that is subjected to vibrations by a vibrator, the large number of springs are moved inside the container, while being arranged in a row by vibrations, and the springs are fed one by one to the operator via a conveying path for feeding.
However, among the large number of springs loaded into the container, two or more springs can be tangled. Accordingly, there are spring feeders equipped with a means for separating a plurality of tangled springs into individual springs. Further, among the types of springs that are handled by the spring feeders, there are springs of a very small size. Such miniature springs can be easily tangled, or deformed and damaged and are therefore very difficult to handle. The tangled miniature springs are difficult to detangle, and when they are separated, the miniature springs can be easily damaged. Further, when poorly handled, the miniature springs can be deformed.
A device provided with a rotary vane that rotates with a high speed is known as a means for separating a plurality of tangled springs. In such a device, a plurality of tangled springs collide with the aforementioned rotary vane that rotates with a high-speed and are scattered. Due to the impact during the collision, the tangled springs are forcibly separated. However, when such a separation means is used, the tangled springs collide with the rotary vane that rotates with a high speed and the springs themselves are subjected to strong impacts. In particular, in a case of miniature springs of a very small wire diameter, a sufficient resistance to the impacts occurring during collision with the rotary vane cannot be ensured, the spring shape is deformed or the miniature springs are elongated or broken, thereby creating defective spring products. The inventors have already addressed this problem and made it possible to separate the tangled miniature springs, practically without damaging the springs, and feed the miniature springs one by one to an operator (Japanese Patent No. 3386401).
In a case where miniature springs are present among the springs, because the wire diameter thereof is very small, as described hereinabove, the defective products that have already been deformed can be present at a stage before loading into the spring feeder. Further, even with the separation means provided in the spring feeder disclosed in Japanese Patent No. 3386401, the tangled miniature springs still can fail to separate, although the probability of such an event is extremely low. Such defective miniature springs that are not in the normal state can be mixed together with the normal miniature springs, and the defective miniature springs can be conveyed to the final conveying path of the spring feeder.
The defective miniature springs can be of various types. For example, a single miniature spring can be slightly arc-like curved with respect to the axial line in the compression-elongation direction. The defective miniature springs of this type can enter the final end portion of the conveying path for feeding of the spring feeder. Further, in a state in which a plurality of springs are tangled, the springs constitute an almost linear row-like configuration along the compression-elongation direction thereof and can enter in this state the final end portion of the conveying path for feeding of the spring feeder. Usually, the conveying path outside of the spring feeder is a groove-like passage and the conveying direction is most often shaped along an almost arc-like line along the outer circumference of the spring feeder body.
In order to enable the groove in the final end portion of the conveying path for feeding to feed the miniature springs one by one, the groove in this portion is formed to have a width that is sufficiently small to pass only one miniature spring. Because of such a configuration, a defective miniature spring such as described hereinabove can be easily caught in the groove-like passage of the conveying path for feeding (in particular, in a zone where the passage is curved in an arc-like shape) in the final end portion of the conveying path for feeding of the spring feeder. For this reason, a plurality of the miniature springs that follow the defective miniature spring can jam the passage and the conveying of the springs can be stopped.